I upgraded to Debian testing/trixie, and my network printer stopped appearing in print dialogs. These are notes from the debugging session. Check firewall configuration I tried out kde, which installed plasma-firewall, which installed firewalld, which closed by default the ports used for printing. For extra fun, appindicators are not working in Gnome and so firewall-applet is currently useless, although one can run firewall-config manually, or use the command line that might be more user frie...